Many circuit implementations require the designer to devise a circuit that handles different input signals having separately referenced signal levels which are not referenced to the supply voltage level of the circuit. Conventional solutions implement two separate conversion circuits that receive a separate input signal and external select signal to determine the signal level reference of the received input signals and translate the appropriate input signal to a supply voltage referenced level using the appropriate conversion circuit. For example, a circuit may receive an emitter coupled logic (ECL) reference level signal or a pseudo ECL (PECL) reference level signal. It is therefore desirable to have a single circuit that can accept either ECL level or PECL level signals at a single input and translate the received input signal into an output signal having an appropriate supply voltage referenced signal level.
From the foregoing it may be appreciated that a need has arisen for a device that can accept different input signals having separately referenced signal levels and produce an output signal having a supply voltage referenced signal level. A need has also arisen for a single circuit that can accept separately referenced signal levels at a single input and generate an output signal having a supply reference signal level therefrom.